PUBLIC HEALTH RELEVANCE: Men who have sex with en re the most impacted risk group in the US HIV epidemic;among MSM, black MSM are disproportionately affected. The increased HIV prevalence and incidence among black MSM are not explained by individual-level risk behaviors. Sexual network characteristics have been demonstrated to be key drivers of heterosexual HIV epidemics in the US, and increased understanding of how black and white MSM sexual networks differ may lead to improved HIV prevention approaches for MSM.